Deterministic positivity violations can be addressed by either redefining the target population, redefining the parameter of interest, or by opting for parametric (or "local") identification.[1]} Redefining the target population works by modifying the target population to one where deterministic positivity is no longer violated. Returning to Table 1, the target population could be redefined to consist of only those without both \(V=0,W=0\)  in \(S=1\) . The ACE for the \(\mathbf {Z}\) -conditional \(S=1\)  target population,
\(E[Y^1 | V\ne 0,W\ne 0] - E[Y^0 | V\ne 0,W\ne 0]\) 
